Seminar

Active stresses and mechanics of intra/extracellular networks

Abstract

Much like the bones in our bodies, the cytoskeleton consisting of filamentous proteins largely determines the mechanical response and stability of cells. Similarly, extracellular networks contribute to tissue mechanics. Unlike passive materials, however, living cells are kept far out of equilibrium by metabolic processes and energy-consuming molecular motors that generate forces to drive the machinery behind various cellular processes. We describe recent advances both in theoretical modeling of such active gels, as well as experiments on reconstituted in vitro acto-myosin networks and living cells. We show how such internal force generation by motors can lead to dramatic mechanical effects, including strong mechanical stiffening. Furthermore, stochastic motor activity can lead to non-equilibrium diffusive-like motion in cells.